Hi! Thank you for your attention to this patch!
On 03.09.2025 00:07, Ilia Evdokimov wrote:
On 04.06.2025 13:40, Alena Rybakina wrote:
Do you have any ideas on how to solve this problem? So far, the only approach I see is to try an alternative plan but I'm still learning this.
Hi,
I've reviewed this patch, and I have suggestion about the approach.
Currently, the patch extends 'convert_EXISTS_sublick_to_join' with quite complex logic (clause collection, volatile checks, rewriting join quals, etc). While it works, the amount of branching and special cases makes the function harder to follow.
Looking at the logic, it seems that a large part of the complexity comes from trying to directly adapt 'convert_EXISTS_sublink_to_join' instead of factoring out a dedicated path. An alternative would be to introduce a separate function 'convert_EXISTS_sublink_to_lateral_join' - with a similar API to 'convert_ANY_sublink_to_join'. Such a function can focus only on the EXISTS-to-join case, while keeping the existing function shorter and easier to reason about.
I even made some first rough sketches of this approach (not a finished patch, just an outline). Of course, it would still need proper adaptation, but I think it demonstrates that the overall structure can be kept simpler.
What do you think about refactoring in this direction?
--
Best regards,
Ilia Evdokimov,
Tantor Labs LLC,
https://tantorlabs.com
I'll look at this. I need some time to consider it.
I'm working on this approach right now. I introduced mutator and made the transformation if it is possible there but I need to fix some bugs.
